The problem of hallucinations looms as an important one for the understanding of the nature of psychopathological conditions. From the viewpoint of actual experience, hallucinations form the epicenter from which the psychosis spreads. The clarification of the hallucinatory process will lead far toward the understanding of psychopathology.Nine years of actual experience have led me to the belief that the crucial factor of the hallucinatory phenomena is the overcoming of the afferent-to- efferent principle. In my experience hallucinations involved complex stimulations of complex patterns of the sensory nervous system. These stimulations were not and could not have been produced by the self of the individual.The complexity of the patterns of the hallucinations suggests the existence of some form of organizing factor. Already existing knowledge as to the physico-chemical nature of the nervous system implies that this factor must at least operate as a physico-chemical agent—say some form of energy system. Difficulties in locating and isolating such a factor within the human organism suggest the possibility of the entrance of an external agent. The question is raised as to whether the prevalent theory of spontaneous generation of psychopathological phenomena may not be retarding the clarification of the actuality behind hallucinations. The possibility that hallucinations may be produced by the intrusion of some psychic infective agent is one that requires attention.Abstract Teaser